Battle of Vittorio Veneto

The Battle of Vittorio Veneto was a major battle of the Italian front of World War I which was fought from 24 October to 4 November 1918 when the Royal Italian Army launched an offensive against Austro-Hungarian forces in the Veneto region of northeast Italy. The battle resulted in the destruction of the Austro-Hungarian Army and Austria-Hungary's armistice with the Allies on 3 November.

Background
The surrender of Bulgaria in late September left Austria-Hungary exposed to attack through the Balkans. Emperor Charles appealed to American President Woodrow Wilson for a peace deal but was rebuffed. In an attempt to stave off political collapse, on 16 October Charles announced a major reform of the constitution, but various ethnic groups were already setting up their own councils to prepare for independence.

Battle
With Austria-Hungary disintegrating, the Italians decided to embark on an offensive that would strengthen their position in future peace negotiations. General Armando Diaz planned an advance from Monte Grappa in the north and across the Piave toward the city of Vittorio Veneto. He had 51 Italian divisions, five French and British divisions, and token Czech and American contingents. On paper, the opposing sides were evenly matched, but in reality the Austro-Hungarian divisions were at half strength, short of artillery, and demoralized. The offensive was launched on 24 October. For two days, the Austro-Hungarian Army fought fiercely, but from 26 October it began to disintegrate. Italian progress was rapid, and Vittorio Veneto fell on 30 October. More than 300,000 Austro-Hungarian soldiers (120,000 Germans, 83,000 Czechs and Slovaks, 60,000 South Slavs, 40,000 Poles, 7,000 Italians, and tens of thousands of Romanians and Ukrainians) were taken prisoner. An armistice was arranged on 3 November, but the Italians continued to advance for another two days, regaining the territory lost after Caporetto.

Aftermath
Defeat in World War I brought about the collapse of the Austro-Hungarian state and the drawing of new borders in Central Europe. Austria-Hungary had in effect ceased to exist before the Armistice was arranged. The country's Poles joined the new Polish state. Czechs and Slovaks declared Bohemia and Moravia independent on 18 October 1918. The South Slavs - Serbs, Croats, and Slovenes - declared independence on 29 October. Hungary quit the union with Austria. Emperor Charles renounced his role as head of state on 11 November.

The peace Treaty of Saint-Germain-en-Laye, concluded with Austria in 1919, reduced Austria to a small republic of predominantly ethnic Germans. Italy gained some territory at Austria's expense, including South Tyrol and Trieste, but less than it had hoped, leaving a legacy of bitterness. By the 1920 Treaty of Trianon, Hungary lost 70% of its prewar territory to Romania, Czechoslovakia, and Yugoslavia.